Santiago González: To nswer your questions it is necessary to have more information. Especially, what kind of dye should be reduced, what will be COD and BOD load, what kind of treatment you want employ. I understand that there should be a coagulation step. Is coaguilation intended as a pretreatment followed by polishing step(s) e.g. biological degradation, chemical oxidation or others. Please give more detailed information about amount and quality of wastewater to be treated.

Best regards

Vit

What do you mean by jar test ??? a treatment plan or to determine some parameters ???

Can you also clarify the extent of treatment that is needed because the usage of the treated effluent also influences the choice of treatment methods. Besides that, the effluent from the dye industry apart from the dye itself also contains many other constituents. So several methods will have to be used to treat the wastewater apart from coagulation.

To clarify my question, currently I work on an environmental consulting agency, so our client is a cloth dyeing industry, currently they do not have any kind of treatment so our objective is to design and built a treatment system to full fill some legislation requirements from my country (Colombia), as you mentioned the treatment system consist on various steps, however our first intention is to decrease de COD, BOD and color among other factors such as pH, temperature etc. As a first step after removing suspended solids, we are planning to prove if a coagulation process with some substances such as Aluminum sulfate, Ferric Chloride and polymers will help us to diminish this characteristics, thats why I am asking about the jar test, the process is carried out on a jar´s test equipment consisting with 4 to 6 jars and different RPM and different concentrations of the coagulant in each jar, so my inquiry is if there is any standard procedure about the RPM for quick and slow agitation and the coagulant concentration when you are designing a treatment system, or if you need to start with the basic and proving different values until you get the values that you need or expect. Because I've been reading some works and tests, and almost on all of them used different values for the quick and slow agitation and concentration interval for the coagulant. Thanks in advance for you information!